Process for the production hydrogenated olefin sulfonates

ABSTRACT

A process for the preparation of complex hydrogenated olefin sulfonate detergent compositions suitable for bar formulation comprises treating an aqueous solution of olefin sulfonates with an oxidizing agent and subsequently hydrogenating the olefin sulfonates.

United States Patent Woo et al. 5] Dec. 23, 1975 PROCESS FOR THE PRODUCTION [56] References Cited HYDROGENATED OLEFIN SULFONATES UNITED STATES PATENTS Inventors: Gar Lek Tiburon; William 3,205,237 9/1965 Blaser et al. 260/513 R Sweeney, Larkspur, both of Calif. 3,424,693 1/1968 Stein et a]. 260/513 R [73] Assignee: Chevron Research Company, San

Francisco, C lif Primary Examiner-James 0. Thomas, Jr. s Assistant Examiner-A. Siege] [22] Flled: 1973 Attorney, Agent, or Firm-G. F. Magdeburger; John 211 App], 352 51 Stoner, Jr.; J. T. Brooks Related US. Application Data [63] Continuation-impart of Ser. No. 317,565, Dec. 22, [57] ABS CT 1972, abandoned, which isacontinuation of Ser. No. A process for the preparation of complex hydroge- 764,632, Oct 3, 1968, abandonednated olefin sulfonate detergent compositions suitable for bar formulation comprises treating an aqueous so- [52] U.S. Cl 260/513 T lution of olefin sulfgnates with an oxidizing agent and [51] Int. Cl. C07C 143/02 bs quently hydrogenating the olefin sulfonates.

Field of Search 260/513 R, 504 R, 513 T 20 Claims, 3 Drawing Figures US. Patent Dec. 23, 1975 PERCENT HYDROGEN ATI ON Sheet 1 f 3 EFFECT OF H O TREATMENT ON OLEFIN SULFONATE HYDROGENATION RATE WITH 70 PD/C CATALYST TEMPERATURE: 66 C PRESSURE: 50 PSI (lNlTlAL)-28 PS1 (FINAL) AOS CONCENTRATION. v0

[1-5 %H o AND 5% CATALYST -1% H 0 AN D 5% CATALYST 7o U A- No H202 AND 5% CATALYST X 60 O y T I I I I O 20 6Q 0 T00 I20 I40 I6 I TIM E,MINUTES US. Patent Dec. 23, 1975 Sheet2of3 3,928,428

EFFECT OF DIFFERENT OLEFIN SULFONATE TREATMENTS ON HYDROGENATION RATE WITH RANEY NICKEL CATALYST Aos CONCENTRATION 15% PRESSUREI 8: PSI (mnmu-so PSI (FINAL) TEMPERATURE; :ooc STIRRING SPEED: 700-800 RPM O-WITH AIR RANEY McKEL X-WITH 3% N 0 ,57RANEY NICKEL D-WITH 3% NAOCL| 5% RANEY NICKEL .UNTREATED A05 5?6 RANEY NICKEL PE RCE NT HYDROGENATION I D l I l B so so :20 M0 m0 TIME MINUTES PEG. 2

US. Patent Dec. 23, 1975 Sheet 3 of3 3,928,428

RECYCLING N CATALYST (970) FOR HYDROGENATION OF l57OLEFIN SULFONATE AT 70 C AND 76 PSI (INITIALJ-SO PSI (FINAL) PRESSURE U z 9 7o X I... Z w so O X 0 A g X Q 50 0 FIRST RUN I A-SECOND RECYCLE RUN l- OXA z 40 X-THIRD RECYCLE RUN '5) III-FOURTH RECYCLE RUN n: I] bf 0 I i I O 20 o 60 80 I00 I20 I40 I I Tl ME, MINUTES PROCESS FOR THE PRODUCTION HYDROGENATED OLEFIN SULFONATES CROSS-REFERENCE TO RELATED I APPLICATIONS tion Ser. No. 317,565, filed Dec. 22, 1972 now abandoned, which in turn is a continuation of application Ser. No. 764,682, filedOct. 3, 1968, now abandoned.

' BACKGROUND OF INVENTION The present invention is concerned with the field of synthetic detergent composition and more particularly with a process for preparing complex mixtures of hydrogenated olefin sulfonates suitable for non-soap bar formulation. v

This application is a continuation-in-part of applica- I Although synthetic detergents have largely replaced I soaps for most household laundering and dishwashing uses, they have found little acceptance in the household toilet bar area. Although the detergent literature is replete with examples of synthetic detergent bars and synthetic detergent-soap combination bars, the toilet bar market continues to be dominated by soap bars.

' Surprisingly, it has been found that the hydrogenated olefin sulfonate detergent material prepared in accordance with the present invention may be used to form excellent detergent toilet bars without the addition of plasticizers. In addition, these bars possess excellent physical properties in such important characteristics as strength, cohesiveness, slough loss, wear rate, latherability, economics and dermatological effects. Particularly important is the lower pH exhibited by detergent bars prepared from hydrogenated olefin sulfonates. Another important feature is that in the preparation of these detergent bars, conventional soap-making equipment and process'techniques may be utilized. A more elaborate description of suitable methods for the prep- =aration of bars including additive agents,perfumes, and

coloring agents is described in US Pat. No. 3,625,9l0.

Previously, the hydrogenation of olefin sulfonates in economically practical proportions has not been satisfactory. Although hydrogenation has been employed as I an analytical technique for determination of the unsatand allows the effective "reuse of the hydrogenation catalyst with little loss of activity.

DESCRIPTION OF THE INVENTION It has now been discovered that the hydrogenation of olefin sulfonates to produce superior detergent compositions is unexpectedly improved by treating the olefin sulfonates with an oxidizing agent prior to hydrogenation. In particular, mixtures of freshly prepared straight-chain olefin sulfonates containing from to 24 carbon atoms'are treated with an oxidizing "agent, such as air, hydrogen peroxide, alkali metal chlorites and hypochlorites, etc., to increase'the hydrogenation,

2 catalyst life and improve the hydrogenatability of the olefin sulfonates, Subsequently, the olefin sulfonates are partially or substantially completely hydrogenated as desired. A

The term olefin sulfonates as used in the present invention defines the complex mixture as may be obtained by the S0 sulfonation of straight-chain olefins containing 10 to 24 carbon atoms. Preferably the sulfonated olefins are neutralized and hydrolyzed prior to hydrogenation. However, hydrolysis may be conducted subsequent to hydrogenation. In addition, neutralization may be conducted before or after hydrolysis and before or after hydrogenation. The sulfonated olefins are hydrolyzed to convert the sultones present to alkene and substituted alkane sulfonic acids. Although A water hydrolysis is preferred, in general the term hycomplex mixture thus obtained may contain substituted alkanesulfonates or sultones and alkene sulfonates as the major components and a lesser proportion-of disulfonated material.

While the general nature of the major components of the complex mixture is known, the specific identity and the relative proportions of the various substituted alkane sulfonates, disulfonates and alkene sulfonates are unknown. Accordingly, a determination of the entire chemical make up is exceedingly difficult and has not heretofore been successfully accomplished. The mixture is best defined by the process used for producing it.

In addition to the preferred straight-chain alphaolefins from wax cracking, suitable olefin starting materials include straight-chain alpha-olefins produced by Ziegler polymerization of ethylene, or internal straightchain olefins prepared by catalytic dehydrogenation of normal paraffinsof by chlorination-dehydrochlorination of normal paraffins. The olefins may contain from 10 to 24 carbon atoms, usually 13 to 22 carbon atoms, and preferablylS to 20 carbon atoms per molecule. Olefin mixtures should have an average molecular weight of at least about 200.

The amount of S0 utilized in the sulfonation reaction may be varied but is usually within the range of 0.95 to 1.25 mols of SO ,per mol of olefin and preferably intherange 1:1 to l:l.l5. Greater formation of disulfonated products is observed at higher So zolefin ratios. Disulfonation may be reduced by carrying the sulfonation reaction only to partial conversion of the olefin, for example by using SO :olefin ratios of less than 1 and removing the unreacted olefins by a deoiling process. In the deoiling process the unreacted olefins may be removed by extracting the reaction product with a hydrocarbon such as pentane. In order toobtain a product of good color, the S0 employed in the sulfonation reaction is generally mixed with an inert diluent or with a modifying agent. Inert diluents which are satisfactory for this purpose include air, nitrogen, S0 dichloromethane, etc. The volume ratio of to diluent is usually within the range of 1:100 to 121. In some cases the reaction of olefin with 80;, can be carried out under subatmospheric pressure without a'diluent.

The reaction product from the sulfonation step may be neutralized with aqueous basic solutions containing compounds such as hydroxides, carbonates and oxides of the alkali metals, alkaline earth metals and ammonium ion. In the preferred method sufficient neutralizing solution may be added to provide for neutralization of the mixture of sulfonic acids subsequently formed by sultone hydrolysis. Generally, one equivalent of base for each mol of S consumed in the sulfonation reaction is added to the sulfonation reaction product.

The proportion of hydroxyalkane sulfonates to alkene sulfonates in the hydrolyzed neutralized product may be varied somewhat by the manner in which neutralization and hydrolysis are carried out. For example, reduced amounts of hydroxyalkane sulfonates are obtained by carrying out the neutralization and water hydrolysis at temperatures in the range of l45200C. while higher yields of hydroxy alkane sulfonate are favored by carrying out the neutralization and hydrolysis at temperatures below 100C. Suitable hydrolysis temperatures range from about 100 to 200C.

Superior detergent properties are exhibited by hydrogenated olefin sulfonates prepared from olefin sulfonates obtained by SO -air sulfonation of C straight- .chain olefins with an SO zair volume ratio of about 1 to 50-100, an sO zolefin mol ratio of 0.95 to 1.15, and neutralization and water hydrolysis of the sulfonation reaction product at temperatures of 145 to 200C using one equivalent of base per mol of SO consumed in the sulfonation step.

Prior to hydrogenation, the olefin sulfonates are pretreated to improve their susceptibility to hydrogenation and to increase hydrogenation catalyst life. The nature of the impurities or poisons which inhibit the hydrogenation of olefin sulfonates is not completely understood. However, it has been discovered that treatment of the olefin sulfonates before hydrogenation with an oxidizing agent substantially eliminates the impurities or poisons inhibiting hydrogenation.

Suitable oxidizing agents are those that have an oxidation potential greater than that of the hydrogen on platinum electrode in acidic solution. This value is =0.000 as defined in Langs Handbook of Chemistry, th Edition, 1969, on pages l22329. The preferred oxidants have an oxidizing value greater than the saturated calomel electrode defined in the same table as +0.244.

The oxidizing agents thus maybe selected from the groups of materials commonly employed as oxidants and in general fall into the following classes.

1. Oxygen or ozone or these materials mixed with usually inert gases. Examples of the latter include air, oxygen in nitrogen, helium, neon, etc., or ozone in these same diluents.

2. Nitrogen oxide compounds including HNO N 0 N0 sodium nitrate, etc.

3. Peroxidic compounds, both organic and inorganic.

The inorganic materials include hydrogen peroxide, sodium peroxide, potassium peroxide, etc. Organic types include such materials as cumene hydroperoxide, benzoyl peroxide, methyl ethyl ketone peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, acetyl peroxide, etc.

4. Compounds having the functional group -OX where X is C1 or Br. This group includes such materials as the alkali metal and alkaline earth metal hypochlorites and chlorates such as sodium hypochlorite, calcium hypochlorite, sodium chlorate,

calcium chlorate, etc. Other useful members are materials such as bromine water, chlorine water, etc.

5. Transition metal compounds in which the metal atoms are in oxidation states which provide the oxidation potential specified. Suitable metals include scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel of the first transition series; metal such as zirconium, molybdenum, etc., of the second transition series; and tungsten, osmium, etc., of the third transition seris. Included are salts having transition metals either in the cation or anion or both. Commonly used examples of these compounds employed as oxidants are sodium dichromate, sodium and potassium permanganate, ferric sulfate, ferric chloride, ceric sulfate, osmium tetroxide, and titanium dioxide.

The desired amount of pretreatment of the olefin sulfonates may be affected by variations in the method of sulfonate preparation, the olefin feedstock used, and the duration of time between preparation of the sulfonates and hydrogenation, etc. In particular, the preferred methods of preparing suitable olefin feedstock, such as wax cracking, Ziegler polymerization of ethylene, catalytic dehydrogenation of normal paraffins, and chlorination-dehydrochlorination of normal paraffins necessarily produce varying amounts of impurities which in turn may affect the degree of subsequent hydrogenation. However, although sulfonates from substantially pure olefins may require less pretreatment, pure olefins are economically less desirable and pretreatment is still required.

In general, when oxygen (0 is used as the oxidizing agent, at least 0.05 part per hundred parts of total olefin sulfonate must be present. Preferably from 0.5 to 5 parts per hundred parts of total olefin sulfonate is sufficient. When other oxidizing agents are utilized, they should be employed in amounts equivalent to the oxidizing effect of oxygen (0 in the prescribed range. A good approximation of a sufficient amount of oxidizing agent can be calculated using the theoretically available oxygen for oxidation in the oxidizing agent. For example, when hydrogen peroxide is used for treating an effective amount will vary from 0.1 to 10 parts, preferably 1 to 5 parts per one hundred parts of olefin sulfonate.

Excess oxidizing agents may be used in the present invention and although consumed both by removal of impurities and decomposition in the reaction, they appear not to show any significant improvement in the hydrogenatability of the olefin sulfonates. Of course, where a large abnormal amount of impurities are encountered in the sulfonate the amount of oxidizing agent will have to be increased accordingly. Caution should be exercised to insure the removal, preferably by decomposition, of any excess peroxide agents to avoid explosion hazards.

Treatment of the olefin sulfonates with the oxidizing agent may be successfully accomplished by contacting the oxidizing agent with a solution of olefin sulfonates at a temperature of from 20 to 200C., and preferably 50C. to C., while the mixture is maintained at a pH range of between 1 to 9 and preferably 6 to 8. When treating is conducted at pHs of below 6 the aromatic hydroperoxides, e.g., cumene hydroperoxide should be avoided because of explosion hazards. Mixing shortens treating time, although usually from A to 2 hours at a temperature of from 50 to 120C. is sufficient to remove the impurities. I I

When using gaseous oxidizing agents, such as oxygen, it is necessary that the gas be intimately contacted with the sulfonate solution. Good agitation is especially helpful in promoting sufficient contact. In the preferred air treating process the reactor is charged with the sulfonate solution and then pressured with air to 2050 psig and agitated at 50-l00C. for l to 2 hours.

DESCRIPTION OF DRAWINGS FIGS. 1 and 2 graphically illustrate the difference in percent hydrogenation of olefin sulfonate samples treated in accordance with the present invention and untreated samples.

FIG. 3 illustrates the high activity of the catalyst obtained on recycle runs.

FIG. 1 represents a comparison of Examples 4, 5 and 6 of the present invention. Illustrated in FIG. 2 is a comparison of Examples 7, 8, 9 and 10. FIG. 3 is an illustration of Example 15.

The following examples describe the preparation of olefin sulfontes in accordance with the present invention.

EXAMPLE 1 Preparation of Olefin Sulfonates The reactor used for this sulfonation consisted of a continuous falling film-type unit in the formof a vertical water-jacketed tube. Both the olefin and the SO -air mixture were introduced at the top of the reactor and flowed concurrently down the reactor. At the bottom the sulfonated product was separated from the air stream.

The feed was a striaght-chain l-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: 1% tetradecene, 27% pentadecene, 29% hexadecene, 28% heptadecene, 14% octadecene and 1% nonadecene. This material was charged to the top of the above described reactor at a rate of 306 pounds/hour. At the same time 124.2 pounds/hour of SO diluted with air to 3% by volume concentration of 50;, was introduced into the top of the reactor. The reactor was cooled with water to maintain the temperature of the effluent product within the range of 4346C. The average residence time of the reactants in the reactor was less than two minutes.

After passing out of the sulfonation reactor the sulfonated product was mixed with 612 pounds/hour of 1 1.2% aqueous caustic and heated to 145-150C. in a tubular reactor at an average residence time of 30 minutes in order to hydrolyze and neutralize the sulfonted product. Olefin sulfontes were produced at the rate of 463 pounds per hour as an aqueous solution having a 45% by weight solids content and a pH of 10.8.

A portion of this product was analyzed and shown to be made up of the sodium salts of alkene sulfonic acids, hydroxy alkane sulfonic acids, and disulfonic acids. These three major components were present in a weight ratio of about 50/35/15, respectively.

EXAMPLE 2 Preparation of Olefin Sulfonates A straight-chain l-olefin mixture produced by cracking a highly paraffinic wax and containing 1% tetradecene, 18% pentadecene, 17% hexadecene, 16% heptadecene, 16% octadecene, 14% nonadecene, 13% eicosene, and 5% heneicosene was processed following the procedure of Example 1. Analysis of the product indicated a-weight ratio of 53/34/13 of sodium alkane sulfonates, hydroxyalkane sulfonates and disulfonates, respectively. The product has a pH of about 7-7.5.

EXAMPLE 3 Preparation of Internal Olefin Sulfonates 230 parts of a straight-chain l-olefin mixture similar to that used in Example 2 were charged to a stainless steel kettle equipped with a stirrer, heating means and a temperature recording device along with 6.75 parts of a commercial low alumina cracking catalyst (American Cyanamid Aerocat /85 having SiO and 14-15% M 0 and an average particle size of 60 microns). The resulting mixture was stirred at 400F. for one hour. The product was distilled to recover the C to C olefins having the following composition: 7% l-olefin, 55% 2-olefin, 26% 3:olefin, and 12% of 4-,or greater olefins. The internal olefin mixture was processed in accordance with Example 1 to produce internal olefin sulfonates.

A wide variety of known hydrogenation catalysts may be used in the hydrogenation step. These include the noble metals such as palladium on carbon and ruthenium on alumina and various forms of nickel, such as Raney nickel, nickel on kieselguhr, and other supported nickel catalysts. Raney nickel, nickel on kieselguhr and palladium on carbon are the preferred catalysts.

The amount of catalyst employed in the hydrogenation of olefin sulfontes may vary in a range from about 0.05 to 30% by weight based on the olefin sulfonate present. Increasing the amount of catalyst will usually result in a shortening of the time necessary for complete hydrogenation.

The hydrogenation reaction is usually carried out at temperatures of from about 20C. to 200C. and preferably 70C. to C. At temperatures appreciably above 200C. unnecessary hydrogenation of hydroxyalkane sulfonates and hydrogenative degradation of the product tend to occur.

Hydrogen pressure during the reaction is not a critical variable. Reduction maybe carried out at pressures varying from less than atmospheric to 5000 psig, but preferably from 30 to 200 psig.

Partial or substantially complete hydrogenation of the olefin sulfonates yields: hydrogenated olefin sulfontes as contemplated within the present invention. The following examples describe the preparation of hydrogenated olefin sulfontes.

EXAMPLE 4 Hydrogenation Without Pretreatment The hydrogenation apparatus had a volume of 254 ml. and consisted of a Fisher-Porter glass pressure bottle equipped with a gauge, abursting disk, gas inlet and exit lines with necessary valves, and a Teflon-coated magnetic stirring bar. The product of Example 2 was diluted with water to give a 25% aqueous solution. Thirty grams of this solution was charged we the pressure bottle. At the same time, an additional 20 ml. of water and 0.376 gram of 5% palladium on carbon were also charged to the bottle. The above-formed mixture was heated to 65C. The system was purged with nitrogen and then with hydrogen. After purging, the system was pressured to 50.0 psig with hydrogen. The magnetic stirrer was started, and the hydrogen pressure was measured periodically. After 133 minutes the hydrogen 7 uptake had ceased and the pressure had dropped only 7.2 psig (32% of theoretical). Only a portion of the double bonds had been reduced.

EXAMPLE 5 Hydrogenation with a 5.0% Hydrogen Peroxide Pretreatment The 25% aqueous solution of the product of Example 2, 100 grams, was stirred and heated to 80C. At this temperature, 4.56 grams of 27.4% hydrogen peroxide solution in water was added. Stirring of the resulting solution was continued for one hour at 78-82C. The treated solution was then allowed to cool to room temperature. No H remained, as indicated by testing with Kl starch paper. The apparatus of Example 4 was charged with 31 grams of this solution. In addition, 19 ml. of water and 0.375 gram of 5% palladium-on-carbn catalyst were also charged. The procedure of Example 4 was then repeated. After 55-60 minutes, the hydrogen pressure had dropped to 27.8 psig, equivalent to 100% of theoretical. No further drop in pressure was observed. The reaction mixture was filtered at 50-60C. to give a clear, yellow-colored filtrate which was evaporated to dryness. 7.5 grams of a fine powder was obtained.

Analysis by bromine number titration showed that there was no residual unsaturation in the product.

EXAMPLE 6 Hydrogenation with a 1% Hydrogen Peroxide Pretreatment Example 5 was repeated except that only 0.913 gram of 27.4% hydrogen peroxide was used in the treating step. Hydrogenation required one hour to absorb 22.2 psi of hydrogen (100% of theoretical). No further pressure drop was observed.

' EXAMPLE 7 Hydrogenation Without .Pretreatment The product of Example 1 was diluted with water to give a 26% solution. The apparatus of Example 4 was charged with 29 grams of this solution, 21 grams of water, and 0.38 gram of Raney nickel. It was purged as before and pressured to 79.5 psig of hydrogen at 100C. The hydrogenation was carried out with vigorous stirring. After 1% hours, only 9.0 psi of hydrogen had been absorbed (31% of theoretical). The catalyst was deactivated and unsuitable for recycling.

EXAMPLE 8 Hydrogenation with an Air Pretreatment The product of Example 1 was diluted to a 26% aqueous solution with water and 30 g. of this was charged to the apparatus of Example 4. The system was filled with air to 50 psig at room temperature. It was then stirred and heated to 100C. and held at this temperature for one hour. After cooling and venting, grams of water and 0.38 gram of Raney nickel were added to the system. It was then purged with nitrogen and hydrogen as before and finally filled with hydrogen to a pressure of 79.5 psig at 100C. The reaction was carried out with vigorous stirring. After 1% hours the pressure had dropped to 48.0 psig (100% of theoretical).

EXAMPLE 9 Hydrogenation with a 3% Hydrogen Peroxide Pretreatment The product of Example 1 was diluted to a 26% aqueous solution. To 160 pounds of this solution heated to C. in a 50-gallon glass-lined kettle there was added 3.6 pounds of 35% hydrogen peroxide. The resulting solution was stirred at 78-82C. for one hour. It was then cooled. No hydrogen peroxide remained. The apparatus of Example 4 was charged with 30 grams of this material, 20 grams of water, and 0.38 gram of Raney nickel. Hydrogenation was carried out as in Example 8. Complete hydrogenation (29.3 psi pressure drop) required two hours.

EXAMPLE l0 Hydrogenation with a Sodium Hypochlorite Pretreatment The reaction product of Example 1, 92.1 parts, was stirred and heated to 80C., at which point 7.9 parts of a 15% sodium hypochlorite solution was added. Stirring was continued at 5080C. for one hour. The solution was cooled and analyzed for surface active material by a Hyamine titration [Referencez House and Darragh, Anal. Chem. 26, 1492 (1954)]. It was 39.6% active. Enough water was added to give a 25% solution.

The apparatus of Example 4 was charged with 30 grams of this solution, 20 grams of water, and 0.38 gram of Raney nickel. Hydrogenation was carried out as in Eample 8. After 1 /2 hours the hydrogen pressure had dropped 26.5 psi of theoretical).

EXAMPLE 11 Hydrogenation with a Nonpreferred Catalyst The procedure of Example 5 was repeated except that 5% palladium-on-barium sulfate was used as a catalyst in place of palladium-on-carbon. Hydrogenation took place as before. Filtration of the hot reaction mixture, however, gave a milky filtrate probably due to barium sulfate leaching from the catalyst support. The adverse alteration of the catalyst system makes palladium-on-barium sulfate unsuitable for the hydrogenation of olefin sulfonates.

EXAMPLE l2 Hydrogenation at Constant Pressure The apparatus for this hydrogenation consisted of a 1-liter Magne-Drive autoclave equipped with an accumulator, a constant pressure regulator, and a temperature recording means. The product of Example 1 was diluted with water to a 26% active concentration and was filtered to remove a trace amount of insoluble material. The pH was adjusted to a value of 6.5-7.5, 3850 parts of the filtered 26% active solution in an open glass-lined vessel was heated to 80C. and then parts of 30% hydrogen peroxide was added and stirred for one hour at this temperature, after which time no hydrogen peroxide remained.

After cooling the above solution to room temperature, 650 grams of it was charged to the previously described autoclave along with 8.5 grams of Raney nickel. The system was purged with nitrogen and with hydrogen. It was then charged with hydrogen to about 50 psig.

The autoclave was warmed to 100C., at which tem perature hydrogen was again introduced to bring the pressure up to 100 psig. The hydrogen pressure was maintained constant at 100 psig throughout the turn. However, the pressure drop in the accumulators was recorded. After 1% hours of stirring at this temperature and pressure, and after which time there was no addi- 9 tional hydrogen uptake, the solution was cooled to about 7080C. It was filtered at this temprature and then allowed to cool to room temperature.

Analysis indicated no residual unsaturation.

EXAMPLE l3 Hydrogenation at High Pressure The procedure of Example 12 was followed except that the hydrogenation was carried out at a constant hyrogen pressure of 540 .psig. Again, the uptake of hydrogen stopped after 1% hours of reaction.

Comparison of the hyrogen pressure drop in the accumulators during Runs 12 and 13 showed that in each case 50% hydrogenation occurred after about 15 minutes of reaction, and 75% hydrogenation occurred after 30 minutes of reaction. An additional 20 minutes was required to reach 90% hydrogenation in both runs.

EXAMPLE l4 Hydrogenation of an Unhydrolyzed Olefin Sulfonate l-Hexadecene was sulfonated in a continuous falling film reactor with SO /olefin mol ratio of about 1.2. The product from this reaction, 184 grams, was dissolved in 198 grams of dioxane to give a 48% solution.

Fifty grams of this 48% solution was heated with stirring to 60C. Then, 2.1 grams of 34% hydrogen peroxide was added. Stirring was continued at this temperature for two hours. The solution was allowed to COOl t room temperature.

Of the hydrogen peroxide-treated material, 17.3 grams was diluted to 50 ml. with dioxane was charged to a ZOO-ml. Fisher-Porter bottle along with 0.80 gram of palladium-on-carbon hydrogenation catalyst. The mixture was heated to l4-26C. and pressured to 50.5 psig with hydrogen. After 30 minutes of reaction, the pressure, the pressure had dropped 18.4 psi. No further drop in pressure occurred after this time. This pressure drop corresponds to hydrogenation of 31% of the original olefin-S0 reaction production.

The hydrogenated materials was filtered to remove the catalyst. The dioxane was removed by evaporation at a temperature below 40C. under reduced pressure. In this way, there was obtained 8.3 grams of a low melting solid. A portion of this solid, 6.4 grams, was mixed with 2.0 grams of 50% aqueous sodium hydrox ide in 35 ml. of water and heated at l50-155C. for 2 hours. The water was then removed by evaporation to give a surface-active material.

Analysis showed the final product to contain about 30% each of sodium alkene sulfonate, sodium alkane sulfonate, sodium hydroxyalkane sulfonate, and of disodium disulfonates.

EXAMPLE l5 Reuse of Hydrogenation Catalyst The procedure of Example 9 using the product of Example 2, was repeated, except that 9% of nickel on kieselguhr catalyst was used. After substantially complete hydrogenation, the catalyst was recovered by centrifuging and decantation and used again with additional treated samples of the same olefin sulfonates. The results of the first, second and third recycle runs of the catalyst are shown in FIG. 3. As indicated, the catalyst activity remained surprisingly high.

EXAMPLE 16 Reduction of an lsomerized Olefin Sulfonate A sample of pure l-hexadecene was isomerized and distilled in essentially the same way as in Example 3 to give a mixture of hexadecenes. The analysis was as follows: l-hexadecene, 7.6%; 2-hexadecene, 55%; 3- and higher hexadecenes, 37.4%. This hexadecene mixture was sulfonated, neutralized and hydrolyzed in essentially the same way as in Example 1. 7.5 g. of the hexadecene sulfonates were subjected to a 3% hydrogen peroxide treatment as in Example 9. Then reduction was carried out using 15% of a 5% palladium-oncarbon catalyst under conditions similar to those of Example 5. A total of 11 pounds of hydrogen pressure drop was observed. An NMR analysis indicated complete hydrogenation.

EXAMPLE 17 Reduction of an Alcohol Hydrolyzed Olefin Sulfonate Example 1 was repeated, except that the product of sulfonation was collected in absolute ethanol, rather than in caustic. This solution, containing 53% of the olefin-S0 adduct was held for days at a temperature of 2425C. At the end of this time, 51 grams of the solution was mixed with 2.4 grams of 34% hydrogen peroxide, and stirred at 5060C for 2 hours. Then 15.8 grams of the treated solution was diluted to 50 ml. with absolute ethanol and 0.80 grams of 5% palladiumon-carbon was added. The mixture was charged to a hydrogenation apparatus under 50 psig of hydrogen. It was vigorously stirred at 23 to 29C as the pressure decreased to 37 psig and then held constant. Analysis showed that the monosulfonic acid product consisted of 47% ethoxyalkane sulfonic acid and 53% alkane sulfonic acid.

When the product of Example 3 is hydrogenated in accordance with the procedure of Example 9, complete hydrogenation of internal olefin sulfonates occurs.

EXAMPLES 18-27 The following examples illustrate the present process using a variety of oxidizing agents. Olefin sulfonate for these examples was prepared as in Example 1 except that a small laboratory sulfonation unit was employed. The sulfonation unit consisted of a 5 mm. ID. 3-foot, jacketed falling film reactor equipped with an inlet weir for the olefin feed, a central 3 mm. O.D. sulfur trioxideair inlet tube, followed by a 1% inch by 4 inch post reactor tube. This reactor was continuously charged with olefin at a rate of 4.38 grams/min. Simultaneously there was added 1.87 grams/min. of S0 diluted to 5% by weight in air (an olefin/S0 mol ratio of 1.2/1). The temperature of the outer surface of the reactor wall was maintained in the range of 45 to 65C by circulating cooling water in the jacket. The sulfonation product was collected for min. by discharging it directly into a stirred caustic solution (442 g. of 8.37% NaOH).

The neutralized sulfonate was hydrolyzed by heating in a stirred autoclave at C for 20 minutes. The solution was diluted to 25% sulfonate and the pH adjusted to 8. One hundred gram portions were treated by the procedure of Example 5 but with various agents being used in place of hydrogen peroxide, as shown in Table 1. The solutions were heated at 80C for 2 hours. Special care was taken to avoid contact with air during the sulfonate preparation and the treating step. After treating, any suspended matter was removed and the pH adjusted to 8.

Each of the solutions was diluted to sulfonate and 50 g. of this solution was hydrogenated with 5% palladium on carbon catalyst as in Example 4. The amount of hydrogen absorbed was determined after 30 based on assumed total molar unsaturation of 57.5% treatment done at pH 1 benzoyl peroxide These examples show that a number of common oxidants are effective according to this invention. Their oxidation potential should preferably be approximately equal to or greater than ferrous ion.

Ferrous sulfate, which was used in Example 26, was not effective in oxidizing the catalyst poisoning impurities. Ferrous sulfate has an oxidizing potential of 0.44. Sodium chlorate employed in Example which was effective has an oxiation potential of +0.35. Many oxidants are more effective at low pH. This is illustrated by Examples 23 and 24. Neutral nitrate ion has an oxidation potential of 0.01. In acid its potential is 0.81.

It should be understood that while the total steps involved in going from the direct product of sulfonation of the olefin to the hydrolyzed, neutralized and hydrogenated product are ordinarily performed in the sequence: hydrolysis and neutralization occurring almost simultaneously followed by hydrogenation, the steps may be varied without substantially affecting the quality of the product. Thus neutralization may be effected in cold solution and thus completely separated from hydrolysis. Conversely, hydrolysis may be carried out in acidic solution by simply adding water to the sulfonation product and heating. In this case neutralization may be carried out by adding base to the mixture either before or after hydrogenation. Likewise, the sulfonation product may be hydrogenated before the other steps. In this case water is usually added to the sulfonation product and oxidation and hydrogenation are effected.

ln some cases it is advantageous to stop with an intermediate product. For example, the acid hydrolyzed and hydrogenated product may be shipped as an acidic product which may then be neutralized at the receiving point and compounded into detergent in the form of flakes, bars, etc. I

While the character of this invention has been described in detail with numerous examples, this has been done by way of illustration only and without limitation of the invention. It will be apparent to those skilled in the art that modifications and variations of the illustrative examples may be made in the practice of the invention within thescope of the following claims.

1 claim:

1. In a process for preparing mixtures of hydrogenated olefin sulfonates by hydrogenating a sulfonated product produced by sulfonating straight chain olefins with S0 the hydrogenation being carried out at temperatures of from about 20C to about 200C in the presence of 0.05 to 30% by weight based on the sulfonated product of a hydrogenation catalyst until from 50 to percent of the carbon-carbon double bonds in the product are saturated, the improvement which comprises treating said sulfonated product immediately prior to hydrogenation with an oxidizing agent having an oxidation potential greaterthan that of the hydrogen on platinum electrode in an acidic solution, wherein said oxidizing agent is employed in sufficient quantity to provide at least 0.05 parts of oxygen or the oxidizing equivalent of another oxidizing agent per hundred parts of the sulfonated product.

2. The process of claim 1 in which the oxidizing agent has an oxidizing potential greater thanthat of the saturated calomel electrode.

3. The process of claim 1 wherein the oxidizing agent is oxygen.

4. The process of claim 1 in which the oxidizing agent is oxygen dissolved in an inert gas.

5. The process of claim 4 wherein the oxidizing agent 1s air.

6. The process of claim 1 wherein the oxidizing agent is hydrogen peroxide.

7. The process of claim 1 wherein the sulfonation product is hydrolyzed prior to oxidation and hydrogenation.

8. The process of claim 1 wherein. the sulfonation product is neutralized with a base prior to oxidation and hydrogenation.

9. The process of claim 8 in which the base is selected from the group consisting of alkali metal and alkaline earth metal oxides, hydroxides and carbonates.

10. The process of claim 1 wherein the sulfonation product is hydrolyzed and neutralized with an aqueous solution of a base prior to oxidation and hydrogenation.

11. The process of claim 10 in which the base is selected from the group consisting of alkali metal and alkaline earth metal oxides, hydroxides and carbonates.

12. The process of claim 8 further characterized in that the product of hydrogenation is hydrolyzed to remove the sultone present in the product.

13. A process for preparing mixtures of hydrogenated olefin sulfonates which comprises sulfonating straight-chain olefins containing from 10 to 24 carbon atoms with S0 wherein said sulfonated olefins are subsequently subjected to the steps of: g

a. treating with an oxidizing agent selected from the group consisting of oxygen, oxygen diluted with inert gases, ozone, alkali metal hypochlorites, alkaline earth metal hypochlorites, alkali metal chlorites, alkaline earth metal chlorites, hydrogen peroxide, sodium peroxide, acetyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and t-butyl hypochlorite, in sufficient quantity to provide at least 005 part of oxygen per hundred parts of olefin sulfonate or the oxidizing equlvalent of another of said oxidizing agents, and hydrogenating said" treated sulfonated olefins, in the presence of 0.05 to 30% by weight based on the olefin sulfonate of a hydrogenation catalyst at temperatures of from about 20C to 200C, until from 50 to 100 percent of the unsaturated carbon-carbon bonds therein are saturated; and

b. adding to the product of step (a) an aqueous solution of a base selected from the group consisting of ammonium, alkali metal and alkaline earth metal hydroxides, carbonates and oxides, in an amount sufficient to hydrolyze the sultones present in the sulfonated olefin product to sulfonic acids and to provide for the neutralization of the sulfonic acids present.

14. A process for preparing mixtures of hydrogenated olefin sulfonates which comprises sulfonating straight'chain olefins containing from l to 24 carbon atoms with S0 wherein said sulfonated olefins are subsequently subjected to the steps of:

a. addition of an aqueous solution of a base selected from the group consisting of ammonium, alkali metal and alkaline earth metal hydroxides, carbonates, and oxides, in an amount sufficient to hydrolyze the sultones present in the sulfonated olefin product to sulfonic acids and to provide for the neutralization of the sulfonic acids present; and

b. treating the product of step (a) with an oxidizing agent selected from the group consisting of oxygen, oxygen diluted with inert gases, ozone, alkali metal hypochlorites, alkaline earth metal hypochlorites, alkali metal chlorites, alkaline earth metal chlorites, hydrogen peroxide, sodium peroxide, acetyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and t-butyl hypochlorite, in sufficient quantity to provide at least 0.05 part of oxygen per 14 hundred parts of olefin sulfonate or the oxidizing equivalent of another of said oxidizing agents, and hydrogenating the treated product in the presence of0.05 to 30% by weight based on the olefin sulfonate ofa hydrogenation catalyst at temperatures of from about 20C to 200C until from 50 to 100 percent of the unsaturated carbon-carbon bonds therein are saturated.

15. A process as in claim 14 wherein the S0 is provided in the form of SO, in an inert diluent.

16. A process as in claim 15 wherein the olefins are straight-chain olefms and contain from 15 20 carbon atoms.

17. A process as in claim 16 wherein the oxidizing agent is selected from the group consisting of the alkali metal and alkaline earth metal hypochlorites and chlorites, hydrogen peroxide, ozone, oxygen and oxygen diluted with inert gases.

18. A process as in claim 17 wherein the treating is conducted on a 10-35 percent water solution of sulfonated olefins, maintained at a pH of 6-8, and at temperatures of from 50 to 120C.

19. A process as in claim 18 wherein the oxidizing agent is utilized in an amount of from 0.5 to 5 parts per hundred parts of sulfonated olefin.

20. A process as in claim 19 wherein from to percent of the unsaturated carbon-carbon double bonds are hydrogenated.

U NITED STATES PATENT AND TRADEMARK OFFICE QETEIQATE 0F QGRECTION PATENT NO. 1 3,928,428

DATED December 23, 1975 iNvENToms) Gar Lok Woo and William A. Sweeney It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 12, line 62, "equlvalent" should read -equivalent-.

Col. 14, line 13, "15 20" should read --l5 to 20-.

Signed and Scaled this ei hteenth O [SEAL] g v FMay1976 A ttesr:

RUTH C. MASON C. MARSHALL DANN Arresting ()j/rcer Commissioner uj'larems and Tradt marks 

1. IN A PROCESS FOR PREPARING MIXTURES OF HYDROGENATED OLEFIN SULFONATES BY HYDROGENATING A SULFONATED PRODUCT PRODUCED BY SULFONATING STRAIGHT CHAIN OLEFINS WITH SO3, THE HYDROGENATION BEING CARRIED OUT AT TEMPERATURES OF FROM ABOUT 20:C TO ABOUT 200*C IN THE PRESENCE OF 0.05 TO 30% BY WEIGHT BASED ON THE SULFONATED PRODUCT OF A HYDROGENATION CATALYST UNTIL FROM 50 TO 100 PERCENT OF THE CARBON-CARBON DOUBLE BONDS IN THE PRODUCT ARE SATURATED, THE IMPROVEMENT WHICH COMPRISES TREATING SAID SULFONATED PRODUCT IMMEDIATELY PRIOR TO HYDROGENATION WITH AN OXIDIZING AGENT HAVING AN OXIDATION POTENTIAL GREATER THAN THAT OF THE HYDROGEN ON PLATINUM ELECTRODE IN AN ACIDIC SOLUTION, WHEREIN SAID OXIDIZING AGENT IS EMPLOYED IN SUFFICIENTLY QUANTITY TO PROVIDE AT LEAST 0.05 PARTS OF OXYGEN OR THE OXIDIZING EQUIVALENT OF ANOTHER OXIDIZING AGENT PER HUNDRED PARTS OF THE SULFONATED PRODUCT.
 2. The process of claim 1 in which the oxidizing agent has an oxidizing potential greater than that of the saturated calomel electrode.
 3. The process of claim 1 wherein the oxidizing agent is oxygen.
 4. The process of claim 1 in which the oxidizing agent is oxygen dissolved in an inert gas.
 5. The process of claim 4 wherein the oxidizing agent is air.
 6. The process of claim 1 wherein the oxidizing agent is hydrogen peroxide.
 7. The process of claim 1 wherein the sulfonation product is hydrolyzed prior to oxidation and hydrogenation.
 8. The process of claim 1 wherein the sulfonation product is neutralized with a base prior to oxidation and hydrogenation.
 9. The process of claim 8 in which the base is selected from the group consisting of alkali metal and alkaline earth metal oxides, hydroxides and carbonates.
 10. The process of claim 1 wherein the sulfonation product is hydrolyzed and neutralized with an aqueous solution of a base prior to oxidation and hydrogenation.
 11. The process of claim 10 in which the base is selected from the group consisting of alkali metal and alkaline earth metal oxides, hydroxides and carbonates.
 12. The process of claim 8 further characterized in that the product of hydrogenation is hydrolyzed to remove the sultone present in the product.
 13. A process for preparing mixtures of hydrogenated olefin sulfonates which comprises sulfonating straight-chain olefins containing from 10 to 24 carbon atoms with SO3, wherein said sulfonated olefins are subsequently subjected to the steps of: a. treating with an oxidizing agent selected from the group consisting of oxygen, oxygen diluted with inert gases, ozone, alkali metal hypochlorites, alkaline earth metal hypochlorites, alkali metal chlorites, alkaline earth metal chlorites, hydrogen peroxide, sodium peroxide, acetyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide and t-butyl hypochlorite, in sufficient quantity to provide at least 0.05 part of oxygen per hundred parts of olefin sulfonate or the oxidizing equlvalent of another of said oxidizing agents, and hydrogenating said treated sulfonated olefins, in the presence of 0.05 to 30% by weight based on the olefin sulfonate of a hydrogenation catalyst at temperatures of from about 20*C to 200*C, until from 50 to 100 percent of the unsaturated carbon-carbon bonds therein are saturated; and b. adding to the product of step (a) an aqueous solution of a base selected from the group consisting of ammonium, alkali metal and alkaline earth metal hydroxides, carbonates and oxides, in an amount sufficient to hydrolyze the sultones present in the sulfonated olefin product to sulfonic acids and to provide for the neutralization of the sulfonic acids present.
 14. A process for preparing mixtures of hydrogenated olefin sulfonates which comprises sulfonating straight-chain olefins containing from 10 to 24 carbon atoms with SO3, wherein said sulfonated olefins are subsequently subjected to the steps of: a. addition of an aqueous solution of a base selected from the group consisting of ammonium, alkali metal and alkaline earth metal hydroxides, carbonates, and oxides, in an amount sufficient to hydrolyze the sultones present in the sulfonated olefin product to sulfonic acids and to provide for the neutralization of the sulfonic acids present; and b. treating the product of step (a) with an oxidizing agent selected from the group consisting of oxygen, oxygen diluted with inert gases, ozone, alkali metal hypochlorites, alkaline earth metal hypochlorites, alkali metal chlorites, alkaline earth metal chlorites, hydrogen peroxide, sodium peroxide, acetyl pEroxide, t-butyl hydroperoxide, cumene hydroperoxide and t-butyl hypochlorite, in sufficient quantity to provide at least 0.05 part of oxygen per hundred parts of olefin sulfonate or the oxidizing equivalent of another of said oxidizing agents, and hydrogenating the treated product in the presence of 0.05 to 30% by weight based on the olefin sulfonate of a hydrogenation catalyst at temperatures of from about 20*C to 200*C until from 50 to 100 percent of the unsaturated carbon-carbon bonds therein are saturated.
 15. A process as in claim 14 wherein the SO3 is provided in the form of SO3 in an inert diluent.
 16. A process as in claim 15 wherein the olefins are straight-chain olefins and contain from 15 20 carbon atoms.
 17. A process as in claim 16 wherein the oxidizing agent is selected from the group consisting of the alkali metal and alkaline earth metal hypochlorites and chlorites, hydrogen peroxide, ozone, oxygen and oxygen diluted with inert gases.
 18. A process as in claim 17 wherein the treating is conducted on a 10-35 percent water solution of sulfonated olefins, maintained at a pH of 6-8, and at temperatures of from 50* to 120*C.
 19. A process as in claim 18 wherein the oxidizing agent is utilized in an amount of from 0.5 to 5 parts per hundred parts of sulfonated olefin.
 20. A process as in claim 19 wherein from 75 to 100 percent of the unsaturated carbon-carbon double bonds are hydrogenated. 